U.S. patent number 4,575,371 [Application Number 06/738,509] was granted by the patent office on 1986-03-11 for urinary catheter.
Invention is credited to Eric Hylerstedt, Percy Nordqvist.
United States Patent |
4,575,371 |
Nordqvist , et al. |
March 11, 1986 |
Urinary catheter
Abstract
The present invention discloses a urinary catheter with a
retention member in the form of an expandable balloon. The
expandable balloon is arranged below the inlet opening and so
designed that in its inflated condition a portion projects forward
past the catheter tip at some distance from the inlet opening. The
unique design of the catheter prevents contact between the wall of
the urinary bladder and the catheter tip thereby avoiding infection
and traumatization of the tissues.
Inventors: |
Nordqvist; Percy (Saro,
SE), Hylerstedt; Eric (Goteborg, SE) |
Family
ID: |
20343621 |
Appl.
No.: |
06/738,509 |
Filed: |
May 28, 1985 |
PCT
Filed: |
April 16, 1982 |
PCT No.: |
PCT/SE82/00124 |
371
Date: |
December 13, 1982 |
102(e)
Date: |
December 13, 1982 |
PCT
Pub. No.: |
WO82/03557 |
PCT
Pub. Date: |
October 28, 1982 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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453899 |
Dec 13, 1982 |
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Foreign Application Priority Data
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Apr 16, 1981 [SE] |
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8102467 |
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Current U.S.
Class: |
604/103.07;
604/103.09; 604/916 |
Current CPC
Class: |
A61M
25/1002 (20130101); A61M 2025/1065 (20130101) |
Current International
Class: |
A61M
25/10 (20060101); A61M 025/00 () |
Field of
Search: |
;604/96-103 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2818119 |
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Nov 1979 |
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DE |
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2089844 |
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Jan 1972 |
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FR |
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Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Holman & Stern
Parent Case Text
This is a continuation of application Ser. No. 453,899, filed Dec.
13, 1982, now abandoned.
Claims
We claim:
1. A urinary catheter comprising an elongated member for
transporting urine through the urethra and provided with a point
end enabling insertion of the catheter through the urethra and
having at least one radial inlet opening close to said point end a
retention member in the form of an expandable balloon arranged
distally with respect to said inlet opening wherein the walls of
the expandable balloon at a portion remote from the catheter tip
being stiffer than the rest of the balloon, the opposite more
flexible portion being arranged when inflated to expand obliquely
forwards, so that the balloon assumes a bowl-like shape, the front
portion of the bowl-like inflated balloon projecting in front of
the catheter tip, thus preventing contact between the mucous
membrane of the urinary bladder and the catheter tip as well as the
radial inlet opening.
2. The urinary catheter according to claim 1, wherein reinforcement
of a portion of the wall of the expandable balloon remote from the
catheter tip is attained by arranging reinforcing ridges on said
portion.
3. The urinary catheter according to claim 1, wherein a
reinforcement of a portion of the wall of the expandable balloon
remote from the catheter tip is attained by making the wall portion
thicker than the rest of the balloon.
4. The urinary catheter according to claim 2, wherein the
reinforcement of the portion of the wall of the expandable balloon
remote from the catheter tip is attained by arranging a tube-like,
resilient member over said portion.
Description
A urinary catheter comprising an elongated member for transporting
urine through urethra and provided with a pointed end enabling
insertion of the catheter through urethra and having at least one
radial inlet opening for the urine close to said pointed end and a
retention member in the form of an expandable balloon arranged at
said end portion below said inlet opening as seen in the position
of use of the catheter in the urinary bladder and intended to when
located in the urinary bladder of the user extend outside said
member in the radial direction thereof and retain the catheter in
position.
Patients who are urinary incontinent or have urine retention are
usually treated with so called balloon catheters of the above
mentioned kind.
A considerable disadvantage of conventional balloon catheters is
that the catheter tip, which projects 1-2 cm in front of the
expanded balloon, often causes irritating injuries in the area
where the catheter tip contacts the mucous membrane of the urinary
bladder. The catheter tip has to be made fairly hard and pointed
for enabling its insertion through the often narrow urethra.
Injuries of this kind have been commonly known by urologists, who
have noticed them at cystoscopies.
The first known systematic investigation of injuries occuring in
connection with the use of urinary catheters is to be found in the
article "Catheter-Induced Haemorragic Pseudopolyps of the Urinary
Bladder" in JAMA 198, 196, 1965. The haemorrhages and polyps
noticed are ascribed to the fact that a negative pressure can arise
in the catheter system. The mucous membrane can then be sucked into
the inlet openings in the catheter tip and be injured. These
injuries then allow possible growth of microorganisms. In order to
improve catheter treatment for the patients and prevent severe
infections caused by these injuries many modifications have been
tried.
Catheters have been treated with antibacterial substances, they
have been coated with hydrophilic polymers and daily installations
with antibacterial lubricants have been made without any obvious
effect.
It has also been proposed to avoid the mucous membrane being sucked
into the holes at the catheter tip, by constructing a catheter with
a ventilating system, which balances the negative pressure.
It has been reported that with such systems no significant
reduction of the rate of bacterial colonization could however be
noticed (Finkelberg Z & Kunin C. M. JAMA 207, 1657, 1969).
Neither could there be noticed any significant difference between
ventilated drainage and conventional drainage in a very extensive
examination of 506 patients and concerning admixture of blood into
the urine during catheter treatment (Monson T. P. & al J. Urol.
117, 216, 1970).
Besides that no significant positive effects have been noticed with
such systems, they are comparatively complicated and expensive as
compared to conventional systems.
An examination by Axelsson et al, published in Acta Path,
Microbiol. Scand., volume II, p. 283-287, has confirmed that it is
the catheter tip, which lies freely in the urinary bladder, which
causes the injuries of the mucous membrane. At this examination it
has by means of scanning electron microscope been shown that
conventional catheter tips have such a configuration that the
mucous membrane is injured when contacting the tip. At a newly
published examination by Ekelund P. et al, Acta Path, Microbiol.
Scand. Sect. A, 87:179-184, 1979 it is finally establiched that
injuries of the urinary bladder cause the disease Polyposis cysta
and that the contact of the catheter tip with the mucous membrane
is the main cause. These changes are according to the examination
found at about 75% of the catheter users after one month.
In the U.S. Pat. No 3,438,375 there is described different catheter
shapes, with which one tries to avoid one of the drawbacks of the
catheters commonly used: sucking of the mucous membrane into the
inlet opening when the urinary bladder is drained through the
catheter. As long as the catheter is closed and there is urine in
the bladder, it is however at first hand the tip of the catheter
that hurts the mucous membrane. In said patent it is also suggested
to arrange the balloon at the front end of the catheter (FIGS. 4a,
14, 22), i.e. the catheter is not in this case provided with a
tip.
In order to enable the insertion of a catheter through especially a
male urethra it is required that the front end of the catheter is
shaped in a way to admit insertion through narrow passages. To coax
a catheter with an almost blunt front end and besides provided with
an empty balloon envelope through the sharp turn below the pelvis
floor muscles and through the narrow passage at the prostate gland
would probably be impossible.
In the U.S. Pat. Nos. 1,922,084 and 3,954,110 there are described
catheters, in which the expandable balloon is arranged at the
catheter tip and by that prevents that the tip irritates the mucous
membrane of the urinary bladder. This however involves certain
drawbacks.
The inflow to the urinary bladder from the kidneys comes by way of
the ureters, which end at the upper corner of frigonumis a way up
(proximally) in the urinary bladder. A catheter drains the urinary
bladder, at which the bladder wall closes round the balloon as soon
as the urine no longer expands the bladder. If the draining hole is
located below (distally) the balloon a continuous drainage cannot
be used, which is the most common catheter treatment method.
Catheter treatment is used against urinary incontinence, the most
frequent reason of which at least for women is a weak pelvis floor
musculature. When a non-incontinent person urinates the muscles of
the pelvis floor slacken, at which the distal part of the urinary
bladder is reshaped to a "funnel". If the pelvis floor owing to
high age or injury, e.g. in connection with child birth, does not
have its normal muscle tonus this "funnel-shape" occurs at distal
parts of the urinary bladder also when the patient does not want to
urinate. A draining hole arranged below (distally) the balloon can
therefore be located so far down in "the funnel" towards urethra
that a satisfactory drainage is not possible.
The U.S. Pat. No. 2,677,375 discloses a catheter which has no tip
which could hurt the mucous membrane. However the drainage hole can
come into direct contact with the mucous membrane of the urinary
bladder and thus at a negative pressure hurt this. Since this
catheter also is flat at the end to be inserted into urethra the
drainage hole has been provided with a cross of latex or rubber. In
order to avoid the difficulty of passing through urethra at the
pelvis floor bend and at the prostate gland a mandrin can be used
at the insertion. This however means a complication.
The object of the present invention is to provide a catheter with
which the above mentioned drawbacks in connection with the use of
catheters are avoided, i.e. which simulataneously has a drainage
hole protected by the balloon and a normally shaped catheter tip,
which will not bump the mucous membrane of the urinary bladder when
the balloon "floats" within a filled urinary bladder. The catheter
hereinbefore described in the introduction is according to the
invention characterized by the fact that said expandable balloon is
so designed, that in expanded condition portions of the balloon
project forwards past the catheter tip at some distance from the
inlet opening and preventing contact between the mucous membrane of
the urinary bladder and the catheter tip as well as the inlet
opening.
The invention will now be further described with reference to some
embodiments shown in the accompanying drawings.
FIG. 1 shows schematically a conventional urinary catheter placed
in the urinary bladder,
FIG. 2 shows schematically a first embodiment of the catheter
according to the present invention placed in the urinary
bladder.
FIGS. 3 and 4 show side views of somewhat modified embodiments of
the urinary catheter according to FIG. 2,
FIG. 5 shows schematically a further embodiment of the urinary
catheter according to the invention placed in a urinary
bladder.
In the drawings corresponding parts in the different figures have
been denoted with the same numerals. Further only the front part of
the urinary catheter, which is placed in the urinary bladder, is
shown in the drawings.
At the previously known catheter 1 according to FIG. 1 the hard and
pointed catheter tip 2 projects in front of the expanded balloon
3.
When the urinary bladder, the walls of which are denoted with the
numeral 4 in the drawing, is emptied from urine it is compressed by
means of its muscles to the shape shown in FIG. 1. The musculature
in the urinary bladder comprises three layers, the inner and outer
of which extend in one plane and the intermediate circularly. The
mucous membrane of the urinary bladder is fixed to the muscle wall
of the urinary bladder. Especially the contraction of the circular
muscle layer results in that the muscle wall with the mucous
membrane is pressed against the catheter tip 2. Thus the tip will
scrape against and irritate the mucous membrane of the urinary
bladder.
When catheter users move or change position they often try to
change the position of the catheter in the urinary bladder. The
hard and pointed catheter tip 2 is then pressed hard against the
mucous membrane of the urinary bladder, which thus can be seriously
injured.
As can be seen from FIG. 1 wall portions of the emptied urinary
bladder are located close to the inlet opening 5 for the urine.
When a negative pressure arises in the catheter system said wall
portions can be sucked into the holes and be hurt.
In FIG. 2, which shows a catheter according to the invention, the
expandable balloon has for the sake of clarity been shown in
cross-section. In the embodiment shown in FIG. 2 of the catheter
according to the invention the expandable balloon 3 has at the area
6 closest the mouth of urethra as seen in the position of use, been
designed with a thicker wall as compared to the rest of the
balloon. The expandable balloon will thus when being inflated
expand in the direction obliquely forwards past the catheter tip,
as is shown in FIG. 2.
An emptied urinary bladder adapts itself substantially to the shape
of the expanded balloon. The muscle arrangement of the urinary
bladder however prevents the muscle wall and the mucous membrane
from being sucked towards the catheter opening 5, when this is
placed at the centre of a bowl-shaped balloon.
There is however no risk at all that the mucous membrane could come
into contact with the hard catheter tip. The fundus of the urinary
bladder can simply not be sucked down into the balloon-bowl since
the so called medial umbilicula ligament will prevent this (see
Frank H. Netter "The Ciba Collection of Medical Illustrations",
Vol. 6, p. 21, second printing N.Y. 1975).
A further advantage of the shape of the expanded balloon according
to FIG. 2, is that the risk of injuries of the urethra is smaller
than for conventional catheters if the catheter unintentionally and
without the expanded balloon having been emptied is drawn out of
the urinary bladder. The portion of the bowl-shaped balloon located
round the tip can be bent somewhat towards the tip when the urethra
presses against the balloon.
The embodiments of the urinary catheter according to the invention
shown in FIGS. 3 and 4 in all essentials correspond to the
embodiment of FIG. 2. Instead of making the wall of the expandable
balloon 3 thicker in the area 6 than the rest of the balloon a
resiliently stretchable tube 7 has according to the embodiment of
FIG. 3 been applied over this area. In the embodiment shown in FIG.
4 the area 6 has instead of thicker wall portions been provided
with reinforcing ridges 8. The tube 7 and the ridges 8 respectively
give the same effect concerning the shape of the expanded balloon
as the thicker wall portion according to FIG. 2.
The catheter according to FIG. 5 is provided with an expandable
balloon comprising two chambers 3' and 3", which are arranged on
opposite sides of the catheter tube and which in expanded condition
project in front of the tip 2. In the embodiment according to FIG.
6 the balloon is arranged as close to the tip that no further
arrangements are necessary for making portions of the balloon
project in front of the catheter tip.
The invention is not limited to the above described embodiments,
but a plurality modifications of are possible within the scope of
the accompanying claims. As an example the bowl-shaped balloon can
be provided by making different portions of the walls of the
balloon of different materials with different extension
properties.
Other types of reinforcing members than the ones shown with
reference to FIG. 4 are, of course, possible.
* * * * *